Robotic Automatic Guided Vehicles (AGV) are used to move parts and assemblies during manufacturing operations. It is known to mount physical contact type safety stop bumpers along the bottom sides of an AVG. Such a bumper will stop the AGV if it comes in contact with a person or object. Such bumpers are costly to maintain and replace. Optical beam safety sensors have not been used on AGVs because of the dirt, high pressure water contamination and physical abuse present in the factory environments in which they operate. It is desired to provide a protective sensor bracket allows for commercially available optical sensors to be used in this environment.